1. Field of the Invention
The present invention relates to a refrigerator.
2. Description of the Related Art
A cooling device for vehicle is disclosed in Japanese Patent Application Laid Open No. 56-43018, the cooling device being configured to drive a compressor included in a refrigeration cycle heat engine by a thermal expander.
In this cooling device, a Rankine cycle is constituted so that a heat medium is vaporized by the heat of an engine to drive an expander, and the heat medium expanded by the expander is, after condensed by a radiator, returned to the engine by a pump, and the compressor of the refrigeration cycle is driven by the expander of the Rankine cycle.
In this cooling device, the refrigeration cycle and the Rankine cycle use the same heat medium (refrigerant), and the refrigerant discharged by the compressor of the refrigeration cycle is condensed by the same radiator as in the Rankine cycle, and then supplied to an evaporator. Therefore, the condensation temperature (pressure) of the refrigeration cycle and the condensation temperature (pressure) of the Rankine cycle are equal to each other.
In the above-mentioned related art, the exhaust side of a rotating shaft of the expander is connected to the suction side of a rotating shaft of the compressor. Therefore, it is needed to provide shaft seal devices respectively on the exhaust side of the expander and on the suction side of the compressor.
If leakage occurs in such shaft seal devices of the refrigeration cycle and the Rankine cycle, the heat medium is leaked out of the system to disable the fulfillment of the capability of the cooling device.